Seal for tower furnace

ABSTRACT

Apparatus forming a seal between the upper end of a tower furnace and a reciprocating feed mechanism that is used to supply feed material to be treated.

O Unlted States Patent 1 91 1 1 3,732,993 Csapo 1 1 May 15, 1973 [54] SEAL FOR TOWER FURNACE [56] References Cited [75] Inventor: Michael Csapo,Wyncote, Pa. UNITED STATES PATENTS [73] ASS'gnee g; Amema 552,372 12/1895 Huber ..266/27 Filed: 17, 1971 Primary ExaminerJohn J. Camby 211 App]. 172 490 Assistant Examiner-Henry C. Yulen Attorney-E. Wellford Mason [52] US. Cl. ..214/18 V, 266/27, 266/25,

34/242, 432/13, 432/239 [571 ABSTRACT 51 11 1. c1. ..F27b 1/00, F27b 9/00 Apparatus forming a Seal between the upper end of a Fleld of Search towel. furnace and a reciprocating feed mechanism that is used to supply feed material to be treated.

3 Claims, 2 Drawing Figures PATENTEB HAY] 51975 FIG.2

SEAL FOR TOWER FURNACE SUMMARY OF THE INVENTION The present invention relates to tower furnaces, and more particularly to a seal between the upper end of such a furnace and a reciprocating member in which feed orifices are formed.

In the operation of a tower furnace to produce lightweight aggregate or ceramic foam, raw material in the form of small particles is dropped through the furnace. As the particles are falling they are heated to fusion temperature and bloated. The furnace is controlled in such a manner that the chamber through which the particles fall is substantially free from turbulence.

When the top of the furnace is sealed, as is usual when making aggregate, no draft is created that will upset the normal flow pattern of the furnace gases. Therefore, the pattern of the falling particles will not be disturbed. When a sliding top is used however, as is frequently the case in the manufacture of ceramic foam, some type of seal is required in order to prevent leakage through the top of the furnace, and therefore the creation of a draft. Such a draft will disturb the falling pattern of the particles so that a non-uniform slab of ceramic foam will be produced. In addition, flow of the hot gases out of the top of the furnace will cause severe damage to the refractories around the openings therein.

It is an object of the invention to provide a simple and effective seal to be used at the upper end of a tower furnace. It is a further object of the invention to provide a sliding seal between the top of a tower furnace and the material supply mechanism used therewith.

In practicing the invention, there is provided a reciprocating cover plate having feed orifices therein. The cover plate is provided with a depending skirt that extends into and is movable in an annular trough which surrounds the top of the furnace. This trough is filled with a sealing liquid which prevents leakage of furnace gases as the cover plate is reciprocated.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

IN THE DRAWINGS FIG. 1 is a section taken on line l--l of FIG. 2. FIG. 2 is a section taken at right angles thereto on line 2-2 of FIG. 1.

DETAILED DESCRIPTION Referring to the drawings, there is shown at l the upper end of a tower furnace which may be generally of the type shown in Blaha US. Pat. No. 3,056,184 which forms a vertically extending furnace chamber 2. The walls of the furnace are provided with a series of rows of burners 3 by which the furnace is heated. The upper end of the furnace is provided with an elongated slot 4 through which the particles to be heated are dropped into the furnace where they fall and are bloated as they fall. Material to be heated which is usually a granular, clay-like material, is fed through a cover plate 5 formed of refractory material supported by a metallic frame 6 that is provided with an extension 7 on each end thereof. These extensions 7 rest on rollers 8 so that the cover plate can be reciprocated. Cover plate 5 is provided with a row of feed orifices 9 immediately above and aligned with feed slot 4. The particulate material is fed to orifices 9 through flexible tubes 11 that are supplied from a hopper 12. These tubes are held in position over the respective orifices by means of fixtures 13 fastened to the frame of the cover plate. The cover plate with its orifices and the feed tubes are reciprocated along the length of the feed slot by means including a constant speed, reversible motor 14 mounted on a suitable frame 15. This motor drives a threaded shaft 16 journaled in and held from axial movement by bearings 17. A sleeve 18 is reciprocated along shaft 16 as it is rotated, with the sleeve being connected by an arm 19 to one of the extensions 7. Motor 14 is operated to reciprocate the cover plate by a projection 19 on sleeve 18 that actuates one or the other of a pair of limit switches 22. When a limit switch is actuated it operates in a conventional manner to reverse the motor thereby to cause sleeve 18 and the parts attached thereto to move in an opposite direction.

The hot furnace gases will escape between the upper end of the furnace and the cover plate if some means is not provided to prevent this from happening. A seal for this purpose includes a skirt 23 extending down wardly from the frame 6 and around the upper end of the furnace. This skirt extends into a rectangular trough 24 that is mounted on the upper end of the furnace structure 1 and around the feed slot 4. It will be noticed from FIG. 2 that the sides of this trough are relatively narrow while FIG. 1 shows that the ends of the trough are wide enough to accommodate movement of skirt 23 throughout the maximum length of reciprocation of the cover plate.

A suitable sealing liquid, which may well be water, is supplied to the trough 24 through a supply pipe 25 that has a regulating valve therein. The liquid rises to a level in the trough that is above the lower edge of skirt 23 with the level being controlled by the height of a pair of dams 26 at each end of the trough. Sealing liquid overflowing from the trough as a result of continual feed of the liquid and as a result of any splashing that may occur as the skirt 23 moves slowly back and forth, goes out through drains 27.

When the furnace is operated, granular particles of material to be heated flow from hopper 12 through tubes 11 and orifices 9 into the furnace chamber where they fall through the heated gases to be bloated. In order to obtain a good pattern of falling particles, the cover plate with its feed orifices 9 is reciprocated slowly back and forth to move the orifices along the length of feed slot 4. The liquid in trough 24 prevents the escape of gases between the reciprocating cover plate and the upper end of the furnace. This construction is both simple and easy to maintain and is very effective in preventing leakage of the furnace gases while in no way affecting the operation of the various parts.

While in accordance with the provisions of the Statutes I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a tower furnace, the combination of structure forming a vertically extending furnace chamber having an upper end, said structure being formed with an elongated feed slot opening into the upper end of said chamber, a cover plate located substantially horizontally above said feed slot and covering the entire slot, said plate being provided with a plurality of feed orifices aligned with and over said feed slot in any position of said cover plate, means to reciprocate said cover plate thereby to move said feed orifices back and forth along said feed slot, and means to form a gas tight seal between the upper end of said structure entirely around said feed slot and said reciprocating cover plate.

2. The combination of claim 1 in which said means to form a gas tight seal comprises means forming a trough that extends around said feed slot adjacent to the upper end of said structure, said cover plate being provided with a skirt extending downwardly into said trough around said feed slot, and a sealing liquid in said trough to a level above the bottom of said skirt.

3. The combination of claim 1 in which said means forming a gas tight seal comprises a first part attached to said structure and surrounding said feed slot, a second part attached to said cover plate and substantially coextensive with said first part and cooperating therewith, and sealing meansbetween said parts. 

1. In a tower furnace, the combination of structure forming a vertically extending furnace chamber having an upper end, said structure being formed with an elongated feed slot opening into the upper end of said chamber, a cover plate located substantially horizontally above said feed slot and covering the entire slot, said plate being provided with a plurality of feed orifices aligned with and over said feed slot in any position of said cover plate, means to reciprocate said cover plate theReby to move said feed orifices back and forth along said feed slot, and means to form a gas tight seal between the upper end of said structure entirely around said feed slot and said reciprocating cover plate.
 2. The combination of claim 1 in which said means to form a gas tight seal comprises means forming a trough that extends around said feed slot adjacent to the upper end of said structure, said cover plate being provided with a skirt extending downwardly into said trough around said feed slot, and a sealing liquid in said trough to a level above the bottom of said skirt.
 3. The combination of claim 1 in which said means forming a gas tight seal comprises a first part attached to said structure and surrounding said feed slot, a second part attached to said cover plate and substantially coextensive with said first part and cooperating therewith, and sealing means between said parts. 